MRI, or Magnetic Resonance Imaging, is a medical imaging technique used in radiology to visualize detailed internal structures. MRI makes use of the property of Nuclear Magnetic Resonance (NMR) to image nuclei of atoms inside the body. MRI provides a good contrast between the different soft tissues of the body, which make it especially useful in imaging the brain, muscles, the heart, and cancers. A ‘signal abnormality’ basically means that the MRI found an abnormality. It is called a signal abnormality because during the MRI, the scanner will detect an abnormality via electromagnetic signals which are similar to radio waves. The scan is known as a T2 scan. It can detect abnormalities of the brain the size of 5 mm and larger. A T2 scan will generate about 20 images of the brain. A signal abnormality does not necessarily mean you have anything drastically wrong with you but MRI is used to detect brain tumours, strokes and play a role in the diagnosis of multiple sclerosis. In addition, it can be used to follow the progression of disorders head trauma, bleeding in the brain, tumours of the pituitary. The technique is also very useful to identify masses that may be impinging on the back of the eyes or ears, it can pick up if there is a birth defect of the brain, brain infections and hormonal disorders. An MRI can also determine the cause of muscle weakness or numbness and tingling, changes in thinking or behaviour, hearing loss, headaches when certain other symptoms or signs are present, speaking difficulties and vision problems. If the scan is abnormal, you will be referred to your physician for further check up and advice. Sometimes a more extensive MRI study with and without Gadolinium contrast will be required. Many of the abnormalities which can be detected will be of little consequence and are not tumours, aneurysms, etc. Most do not require surgery.
